. Author manuscript; available in PMC: 2018 Nov 24.
Published in final edited form as: Lancet. 2018 Nov 10;392(10159):1859–1922. doi: 10.1016/S0140-6736(18)32335-3
This is an Open Access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/).